Log garbage_collection_cutoff alongside the other BlobDB options

Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/6229

Differential Revision: D19191195

Pulled By: ltamasi

fbshipit-source-id: 2a3c4785299641a46e022fc012460b759a689fce

utilities/blob_db/blob_db.cc

@@ -89,6 +89,9 @@ void BlobDBOptions::Dump(Logger* log) const {
   ROCKS_LOG_HEADER(
       log, "                 BlobDBOptions.enable_garbage_collection: %d",
       enable_garbage_collection);
+  ROCKS_LOG_HEADER(
+      log, "                 BlobDBOptions.garbage_collection_cutoff: %f",
+      garbage_collection_cutoff);
   ROCKS_LOG_HEADER(
       log, "                  BlobDBOptions.disable_background_tasks: %d",
       disable_background_tasks);